is it possible?

You know i cannot use URL aliases
One thing i must ask you :

I saw that SEF is overwriting the sefRelToAbs function and includes/sef.php is not used anymore so i think it`s impossible for me to add SEF to my links.
Now, can you point me to the right direction where i can read about sef_ext
or can you tell me in what cases your script loads sef_ext files (i know it should be uploaded into the component directory). Isnt possible to hack this, i mean a backdoor or something to make SEF reads joomla content.
( if it`s possible i`ll learn and write my own )
I hope this make sense.
Thank you again in advance.

SEF Advance extension files (sef_ext.php) are made for 3rd party components only.
The SEF behavior for content is within encoded part of SEF Advance and no modifications can be done there.

As I said, SEF Advance isn't suposed to deal with hacked core files. I suggest you turn your hacks into a real component which will allow you to write the extension file and get SEF URLs for that.

If you still absolutely need SEF Advance to support your content hack the only option you have is to hire me for custom project.